The invention relates to a sulfur curable (and cured) rubber composition which contains one or more pentaerythritol derivatives as pentaerythritol tetrabenzoate (PTB) and/or pentaerythritol tetrakis (3,5-di-tert-butyl4-hydroxyhydrocinnamate) (PTHC) together with a low molecular weight polyester sebacate. Such combination of materials has been observed to increase resistance to tear for a rubber composition. The invention particularly relates to a tire having a component comprised of such rubber composition.
Rubber compositions for various components of tires are typically optimized for their physical properties. For example, for tire treads, the rubber compositions are usually optimized for traction, rolling resistance and/or treadwear.
For such components, as well as other components such as for example tire sidewall, tread base for a tire with a tread of a cap/base construction, are sometimes desired to be provided with a suitable resistance to tear, such as resistance to tear initiation.
In the description of this invention, the term xe2x80x9cphr,xe2x80x9d where used herein, and according to conventional practice, refers to xe2x80x9cparts of a respective material per 100 parts by weight of rubber or elastomerxe2x80x9d.
In the description of this invention, the terms xe2x80x9crubberxe2x80x9d and xe2x80x9celastomer,xe2x80x9d if used herein, may be used interchangeably, unless otherwise prescribed. The terms xe2x80x9crubber composition,xe2x80x9d xe2x80x9ccompounded rubberxe2x80x9d and xe2x80x9crubber compound,xe2x80x9d if used herein, are used interchangeably to refer to xe2x80x9crubber which has been blended or mixed with various ingredients and materialsxe2x80x9d and such terms are well known to those having skill in the rubber mixing or rubber compounding art.
In accordance with this invention, a rubber composition is provided which comprises, based upon parts by weight per 100 parts by weight elastomer (phr);
(A) 100 parts by weight of at least one diene-based elastomer,
(B) about 1 to about 20, alternately about 5 to about 15 , phr of:
(1) pentaerythritol tetrabenzoate (PTB) or
(2) pentaerythritol tetrakis (3,5-di-tert-butyl4-hydroxyhydrocinnamate) (PTHC), and
(C) about 1 to about 20, alternately about 5 to about 15, phr of polyester sebacate having a molecular weight in a range of about 1000 to about 3000 so long as it has a melting point below 0xc2x0 C.
In further accordance with this invention, said rubber composition is provided as a sulfur cured rubber composition.
In additional accordance with this invention, an article of manufacture is provided having at least one component comprised of such rubber composition, or sulfur cured rubber composition.
In further accordance with this invention, a tire having at least one component comprised of said rubber composition, including a sulfur cured rubber composition. Representative examples of such tire components are, for example, tire treads, particularly tire base of a tire having a tread of a cap/base construction, as well as tire sidewalls.